@[DISPLAY] in filenames

We're using Acu 9.2 on Windows - when running a thin client session, we use C$OPENSAVEBOX to select an output folder and filename for a file.  However, when we try writing to that file,setting the filename to "@[DISPLAY]:path\filename", we get a file error 9D.

We can always create the file on the server and then copy it to the client, but that seems like an unnecessary step - since OPENSAVEBOX can access the client, shouldn't we be able to write directly to the client using @[DISPLAY]:?

Basically just looking for confirmation whether or not this is supported under Acu 9.2 for Windows.

Thanks

Tony